Abstract: The hybrid CHB-TVSI multilevel voltage source inverter is a polyphase grid-connected multilevel inverter system has an upper part and lower part that provides output power in three phases. The upper part uses cascaded H-bridge cells having pairs of switched intermediate outputs. DC power sources are connected in series or parallel to track a desired input voltage to feed respective H-bridges, providing an optimum power point tracking (MPPT) of the DC power sources. The lower part, also connected to DC power sources, uses a triple voltage source multilevel inverter that includes three cascaded units, each configured as a three-leg, two-level inverter. The lower part is connected to the upper part, the upper part providing a corresponding polyphase output.

Abstract: The multilevel cascade hexagonal voltage source converter with isolated DC sources has a plurality of polyphase stages, each stage having AC inputs corresponding to a number of phases, and a numerically identical plurality of n outputs, cascaded by connection of the outputs of one stage to the inputs of a next stage. Each stage has plural DC-to-AC converters corresponding to the number of phases, and connected to one of the AC inputs, each having a connection for receiving DC power, and amplifying its AC outputs with the received DC power. The DC-to-AC converters are connected by split inductors, with each split inductor providing an output at a center tap terminal. The inductor half-segments are cross-connected with inductive cross-coupling links inductively connected to the inductor half-segments at opposite sides of the polyphase ring connection. The middle terminals of the n split inductors provide n AC outputs for its respective polyphase stage.